Miglione, Antonella (2024) Novel (bio)sensors and LC-HRMS approaches for the accurate and sustainable monitoring of anthropogenic contaminants and emerging natural toxins. [Tesi di dottorato]

Anteprima

Testo Miglione_Antonella_36.pdf Download (12MB) | Anteprima

Abstract

Climate change and anthropogenic activities, such as pollution, land and water exploitation, have significant impacts on both aquatic and terrestrial ecosystems, leading to environmental degradation and potential human health consequences. The natural occurrence or the introduction of contaminants into the environment may cause adverse changes that affect the health of humans, animals, and plants, as well as damage buildings and other structures. Terrestrial and freshwater ecosystems are particularly vulnerable to climate change, which can lead to changes in wildlife diseases, insect pests, extinction events, biome shifts, wildfires, and drought-related ecosystem changes. This dissertation is focused on emerging contaminants, a class of contaminants characterized by their novelty, ubiquity, and persistence and consequently, reason of challenges for traditional regulatory frameworks and analytical methods. Chapter 1 is focused on two sub-groups belonging to this macro-area: i) anthropogenic contaminants, including heavy metals, drug residues, pesticides, and so on, known to adversely affect physiological systems even when they are present in trace, and ii) emerging natural toxins (e.g. cyclic imines, cyanotoxins and palytoxins), whose risk to the environment and to humans is not fully understood and so tolerance limits for regulation are not established yet by Safety Authorities. As for the clinical practice, as well as for the environmental pollution, the first part of the therapy is represented by an early diagnosis. Consequently, the real purpose of this dissertation is to enhance both the environmental and health monitoring system by improving analytical analysis. In this context, two analytical techniques are exploited, liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS), that provides high reliability towards detection, identification and quantitation of most of the emerging natural toxins in different matrices, and electrochemical (bio)sensors, applied as novel architectures in environmental and health monitoring. In Chapter 2, the main theoretical aspects of the two techniques are briefly presented, focusing on the workflows for targeted and untargeted LC-HRMS analysis and on fabrication, modification, and architectures of electrochemical (bio)sensors. Accordingly, results obtained on these two topics are discussed: in Chapter 3, LC-HRMS approaches for the accurate and sustainable monitoring of emerging natural toxins are presented. Three class of toxins are exploited, the cyclic imines related to the mucilage samples that we analyzed in 2021, when in the north-eastern Aegean sea a mucilage episode occurred, the cyanotoxins and cyanometabolites, that have been the subject of two different studies, one related to the untargeted LC-HRMS applied to microcystin-producing cyanobacterial cultures for the evaluation of the efficiency of chlorine-based treatments commonly used for water potabilization, and the other related to the activities that I carried out as visiting PhD student at Eawag - Department of Environmental Chemistry of the Swiss Federal Institute of Aquatic Science and Technology, about the update and implementation of the CyanoMetDB, applied on the monitoring of key metabolites from cyanobacterial blooms of Planktothrix spp. The last toxins discussed are palytoxin and its congeners and in particular the development of a solid-phase toxin adsorption (SPATT) method based on cross-linked cyclodextrins for monitoring these compounds. In Chapter 4, novel architecture in the field of electrochemical sensors and biosensors are presented. Starting from an integrated electrochemical platform, empowered by paper, for fast nickel detection, in which the classical three electrodes configuration is printed on a polyester substrate and then combined with filter paper in order to (1) store the reagents, (2) collect real samples, and (3) preconcentrate the analyte of interest, we moved on a total paper-based electrochemical strip to detect paracetamol in wastewater, in which our paper-based electrochemical sensor is printed together with a filter paper strip, which gives the possibility of treating complex matrices as wastewater, in situ, and represented a green alternative to common detection methods. Moving on, we proceeded with the characterization and application of porous PHBV-based bacterial polymers to realize novel bio-based electroanalytical (bio)sensors. These alternative substrates have been screen-printed with conductive inks to realize electrochemical strips and applied towards pesticide detection, highlighting the potentiality of PHBV-based materials for future sustainable application in the electroanalytical field. Finally, we focused on electrochemical biosensors for on-glove applications, in which the classical electrochemical strip is integrated in a glove and applied to the detection of pesticides directly on fruit peels. All these new architectures can be successfully implemented in the clinical field and some of these exploited applications are quickly presented in Chapter 5. In conclusion, the exploitation of I) easy-to-use and portable de-centralized approaches and II) validated and reference laboratory-bound methodologies, might represent a step forward beyond the current paradigm: each approach should be seen as an added point for the other one. The obtained information could allow a faster, more selective, cheaper, and easier detection of potentially harmful factors in different matrices, with the purpose to preserve human health and ecosystems.

Downloads

Actions (login required)

Modifica documento